1. Field of the Invention
The present invention relates generally to systems for alerting an occupant of an aircraft that the aircraft is approaching a particular area of an airport and more particularly to an awareness system for providing a tactile alert to the aircraft occupant when the aircraft is approaching a hold line.
2. Description of the Related Art
A runway incursion may be defined as “any occurrence at an airport involving an aircraft, vehicle, person or object on the ground that creates a collision hazard or results in loss of separation with an aircraft taking off, intending to take off, landing or intending to land.”
One such incursion scenario is that of the aircraft traveling beyond a hold line without ATC clearance. Causes for this event vary, but research indicates that causal factors are inadequate navigation awareness including confusion signage as well as excessive operational demands.
This results in lack of local awareness or visually missing local cues for guidance. This will often lead to missing turns or navigating the aircraft beyond a hold line without proper clearance.
Some systems use an aural or visual warning when a hold line has been crossed, adding to the audio clutter in the flight deck. For example, U.S. Pat. No. 6,606,563, entitled Incursion Alerting System, discloses a system for alerting the occupant of a vehicle that the vehicle is in or approaching a zone of awareness. For instance, the system may be used to alert the pilot or flight crew of an aircraft that the aircraft is on or approaching a runway, and may identify the specific runway. Thus, the invention also provides a method of reducing unintentional incursions of taxiing aircraft onto runways. The system generally includes a storage device or memory, a positioning system such as a GPS that typically repeatedly determines the location of the vehicle, an alerting device such as an alarm or display, and a processor, all of which are typically located on the vehicle. The processor typically compares the location of the vehicle with stored location information for various zones of awareness and initiates an alert when appropriate. The processor may take into consideration the velocity and direction of travel of the vehicle. Zones of awareness may be defined by coordinates, such as the end points of line segments. Audible alarms may include a voice warning, and may be able to be silenced until the vehicle leaves the zone of awareness. On aircraft, the system may reference the centerline of the runway, for example, alerting when the aircraft is within 150 feet of the centerline. The system may be disabled when the aircraft is in flight.
Presently, rumble strips are often used to alert automobile drivers of an impending stop or that his vehicle is drifting off a road. Such rumble strips may be a series of textured grooves in the road that cause an automobile to vibrate and its tires to emit a “rumbling” sound as it passes over the strip. This vibration and sound alert the driver that the vehicle is close to the stop or has deviated from the road and the driver may then correct the motion of the vehicle.
U.S. Pat. No. 6,937,165, entitled “Virtual Rumble Strip”, discloses a system for a virtual rumble strip that uses a 3-dimensional audio alert (3-DAA) signal to warn a user operating a vehicle that the vehicle has deviated from a predetermined path. The virtual rumble strip may include a sensor that detects location data for the vehicle, and an alerting mechanism that receives the location data from the sensor. The alerting mechanism may include an audio processing unit that uses the location data and a Head-Related Transfer Function to create the 3-DAA signal. A speaker may then play the 3-DAA signal, which the user may interpret as originating from the direction of the deviation. The user may then respond to the 3-DAA signal by correcting the motion of the vehicle. The alerting mechanism may include a tactile processing unit in communication with a tactile actuator. The tactile processing unit may generate a tactile signal that is sent to the tactile actuator. The tactile actuator may be an electromechanical device that converts the tactile signal into a mechanical movement, such as a vibration.
U.S. Pat. No. 7,363,145, entitled “Ground Operations and Imminent Landing Runway Selection”, discloses a method, computer program product and apparatus for locating aircraft with respect to airport runways, generating and annunciating imminent landing situational awareness advisories as a function of aircraft height above runway.
U.S. Pub. No. 20070241935, entitled “Runway and Taxiway Turning Guidance”, discloses according to an example embodiment, a method that includes receiving data about an aircraft that is moving on a surface using at least a first wheel, the data descriptive of physical characteristics of the aircraft, calculating a first path of the first wheel along the surface using the data, and displaying the first path in relation to a boundary between a first area of the surface and a second area of the surface, the first area safe for the aircraft, the second area unsafe for the aircraft.
The aforementioned prior art focuses on aural alerting which increases audio clutter in the flight deck. Additionally, the prior art does not address that in a high work load environment, there is a potential loss of awareness of local visual cues for impending hold operations.